Mostly out of curiosity, at the convenience market very near my house, I purchased a slice of banana cream pie. It was awesome! And near my home is the only place I would buy a slice of banana cream pie.
When they play at home, the Diamondbacks look like a team heading to the World Series (25 wins, 17 losses). This win-loss record at home is hugely better than each of the last four seasons.
There’s no place like home! Let’s look to understand the reasons.
Reason One: Faced Easy Teams.
Although some have written that the Diamondbacks won more against bad teams than good teams, but that seems more like common sense. Let’s look at the proportion of each type of team.
Did the Diamondbacks mostly face easy teams? At home, the Diamondbacks faced 6 teams with losing records, 2 teams with .500 records, and 5 teams with winning records (games through 22 June). No, the Diamondbacks did not mostly face easy teams.
Reason Two: Winning 1-run games.
At home, the Diamondbacks record is 9 wins and 3 losses in 1-run games. Was it luck? Only a quarter of the games were 1-run games. That seems like a small sample size.
Perhaps home games were won because of luck, but my view is that luck is not a good reason.
Reason Three: Run Differential.
Perhaps the Diamondbacks scored more runs at home, resulting in a positive run differential. Or maybe defense was better, resulting in less runs allowed.
However, in games through 23 June, runs scored (186) exactly equaled runs allowed (186). Looking deeper, in 1-run games the runs-allowed-per-game was within one percent of the season stat (games through 23 June).
The facts argue that run differential was not a good reason.
Crowds of loud, enthusiastic, and D-back friendly fans lifted the quality of play by the Diamondbacks players. Although I’m confident players feel better than when they experience hostile crowds, I’m uncertain whether feeling better improves quality of play. Furthermore, I’m confident that Torey Lovullo excels in motivating his players in each game, regardless of prior game results and regardless of whether it is an away or home game.
Perhaps home crowds made the players feel better, but my view is that was not a good reason.
Reason Five: Disrupted Routines.
When playing home games, players likely have routines, including what time they sleep. When they play away games, their routines are disrupted and their sleep times change, which could reduce the quality of play. However, my view is that significant efforts are made to reduce the disruptions.
Perhaps routine disruption accounts for a small difference, by my view is the difference is much larger than could be caused by small differences in routine.
Reason Six: Quality Starts.
In home games, nearly 50% of games (20 of 42 games) had a quality start by the rotation pitcher. That stat was much better than the season average of 40.5% (games through 23 June). Confirming that it was quality starts that made the difference, the home game win-loss record in quality starts was 16 wins and 4 losses. That was huge, more than enough to explain why the win-loss record was better when playing home games.
A deeper level of analysis might answer the question, “Why did the rotation achieve more quality starts in home games?”
Was it because the best starters pitched more often at home than away? The starters’ percentage of home games seemed balanced with away games. The biggest difference was Soroka with 60% home games and 40% away games. That could account for an expectation of one extra quality start at home, which is not a sufficient explanation.
Was it because pitching at Chase resulted in a higher percentage of quality starts? This must be true, but falls short of being an explanation.
In games through 25 June, only two pitchers had significantly more quality starts at home than away. They were:
Cristopher Sanchez, Phillies, 9 vs 3.Bryce Elder, Braves, 7 vs 3.
What do the Diamondbacks starters have in common with these two pitchers? This question is worth further exploration.
The Diamondbacks had a 25-17 win loss record in home games. Six possible reasons were examined.
In home games, the Diamondbacks had a higher percentage of quality starts (50% vs 40.5%). The home-game quality-start win-loss record was 16 wins and 4 losses, which was more than enough to account for the better record in home games.
On a deeper level, possible reasons for more quality starts at Chase were considered. No satisfying reason was found. One area for further exploration is determining why the Diamondbacks starters are similar to Cristopher Sanchez and Bryce Elder.